Community Organizations in Venezuela: Toward the Disintegration of the Modern State and the Emergence of a "Community Organized" Society?

This paper argues that Venezuelan community organizations (COs) are playing a substantial role in the building of a new social order in which elements such as rights, equity, and justice are being displaced from a universal narrative toward more local narratives. This displacement is enwrapped in a discourse on the political participation of citizens in the running of public affairs, which implies a redefinition of the role of COs and the state beyond the usually accepted sphere of COs. The need to unfold the sense of COs thus becomes paramount for understanding our present and its current manifestations of an epochal change.     

Renal handling of bilirubin photoderivatives

Summary The renal handling of unconjugated bilirubin in the dark and during light exposure was analyzed using an isolated rat kidney preparation. The parameters tested were pigment disappearance from the perfusion medium, pigment uptake by tissue, and its renal clearance. The results indicated that despite the fact that pigment disappearance from the medium was similar for both forms of pigment, the extraction ratio was higher for irradiated pigment than for pigment in the dark. When renal clearance of pigment was plotted vs pigment uptake of tissue, the results indicated that irradiated pigment may be more efficiently removed by the kidney. In addition, data on the rate of secretion of p-aminohippurate suggested that both pigment forms shared a common site for secretion.13 August 1986Acknowledgments. This work was supported by grants from Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET), República Argentina. The valuable technical assistance of J. Pellegrino and E. Luque is gratefully acknowledged. We are also indebted to Dr S. Bravlavsky (Max-Planck Institut für Strahlenchemie, D-4330 Mülheim a. d. Ruhr, FRG) for stimulating discussion, and to Mr B. Leguizamón for secretarial assistance.     

A novel retinoblastoma therapy from genomic and epigenetic analyses

Retinoblastoma is an aggressive childhood cancer of the developing retina that is initiated by the biallelic loss of RB1. Tumours progress very quickly following RB1 inactivation but the underlying mechanism is not known. Here we show that the retinoblastoma genome is stable, but that multiple cancer pathways can be epigenetically deregulated. To identify the mutations that cooperate with RB1 loss, we performed whole-genome sequencing of retinoblastomas. The overall mutational rate was very low; RB1 was the only known cancer gene mutated. We then evaluated the role of RB1 in genome stability and considered non-genetic mechanisms of cancer pathway deregulation. For example, the proto-oncogene SYK is upregulated in retinoblastoma and is required for tumour cell survival. Targeting SYK with a small-molecule inhibitor induced retinoblastoma tumour cell death in vitro and in vivo. Thus, retinoblastomas may develop quickly as a result of the epigenetic deregulation of key cancer pathways as a direct or indirect result of RB1 loss.     

A new species of Proctophyllodes Robin, 1868 (Acari: Proctophyllodidae) from two tanagers of the genus Piranga Vieillot (Passeriformes: Cardinalidae) from North America

A new feather mite species, Proctophyllodes pirangae sp. n. (Acari: Proctophyllodidae) is described from two tanagers of the genus Piranga Vieillot, 1808 (Passeriformes: Cardinalidae) in North America: the Scarlet Tanager, Piranga olivacea (Gmelin) and the Western Tanager, Piranga ludoviciana (Wilson) (Passeriformes: Cardinalidae) from North America. The new species belongs to the anthi species group and differs from the most similar species, Proctophyllodes polyxenus Atyeo and Braasch, by having in males, the aedeagus and genital sheath extending to or slightly beyond the level of setae g, the anterior margin of the opisthogastric shield shallowly concave, and its posterior margin nearly square-shaped, and the lamellae smaller; in females, both the lobar cleft and the transverse band of soft tegument at level of setae h1 are considerably narrower.

www.zoobank.org/urn:lsid:zoobank.org:pub:29B3D157-8114-48EC-AF31-61A99F6D0C3B     

CBP-mediated SMN acetylation modulates Cajal body biogenesis and the cytoplasmic targeting of SMN

The survival of motor neuron (SMN) protein plays an essential role in the biogenesis of spliceosomal snRNPs and the molecular assembly of Cajal bodies (CBs). Deletion of or mutations in the SMN1 gene cause spinal muscular atrophy (SMA) with degeneration and loss of motor neurons. Reduced SMN levels in SMA lead to deficient snRNP biogenesis with consequent splicing pathology. Here, we demonstrate that SMN is a novel and specific target of the acetyltransferase CBP (CREB-binding protein). Furthermore, we identify lysine (K) 119 as the main acetylation site in SMN. Importantly, SMN acetylation enhances its cytoplasmic localization, causes depletion of CBs, and reduces the accumulation of snRNPs in nuclear speckles. In contrast, the acetylation-deficient SMNK119R mutant promotes formation of CBs and a novel category of promyelocytic leukemia (PML) bodies enriched in this protein. Acetylation increases the half-life of SMN protein, reduces its cytoplasmic diffusion rate and modifies its interactome. Hence, SMN acetylation leads to its dysfunction, which explains the ineffectiveness of HDAC (histone deacetylases) inhibitors in SMA therapy despite their potential to increase SMN levels.     

The use of lytic enzymes ofMicromonospora spp. to prepare protoplasts of yeasts

Résumé On met en évidence pour la première fois l'action lytique d'une espèce deMicromonospora qui a le pouvoir de digérer la paroi cellulaire des levures, donnant lieu à la formation de structures possédant des propriétés de protoplastes. Cette enzyme que nous avons déjà partiellement purifée, montre plus d'activité que d'autres systèmes semblables quant à l'obtention de protoplastes ainsi que de meilleures propriétés.